I understand the singular/plural issue but in one exercise in this same "chapter" the sentence was something like "Nous tournons notre chaise ver la fenetre" or something like that and the translation was that in that particular case notre chaise was used for "our chairs". There must be a rule :). Thanks!

I think you are right. In an earlier exercise we had the example of "notre chapeau" to mean one hat each -- and in this set also, "notre chaise" which I took to mean one chair each and which was accepted. ??

I keep typing in the required text, exactly as DL translates it, and it keeps rejecting my identical answer, so I cannot move on - it has done this 3 times. Must be a glitch, I am going to try the word bank.